MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 11
·2037-2043
·
IF 3.741
He Yi,Zhang Xianhui,Yu Haili
We demonstrate a selective and sensitive method for determination of creatinine using citrate-stabilized gold nanoparticles (AuNPs) as a colorimetric probe. It is based on a direct cross-linking reaction that occurs between creatinine and AuNPs that causes aggregation of AuNPs and results in a color change from wine red to blue. The absorption peak is shifted from 520 to 670 nm. Under the optimized conditions, the shift in the absorption peak is related the logarithm of the creatinine concentration in the 0.1 to 20 mM range, and the instrumental detection limit (LOD) is 80 μM. This LOD is about one order of magnitude better than that that of the Jaffé method (720 μM). The assay displays good selectivity over interfering substances including various inorganic ions, organic small compounds, proteins, and biothiols. It was successfully employed to the determination of creatinine in spiked human urine.
The colorimetric assay for creatinine uses citrate-stabilized gold nanoparticles (AuNPs) and a direct cross-linking reaction that occurs between creatinine and AuNPs that causes aggregation of AuNPs and results in a color change from wine red to blue.
研究领域:
生物化学
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纳米医学
·
诊断学
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产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2015
·Vol. 72
·期 11
·3007-3030
·
IF 1.438
Islam Muhammad Remanul,Beg Mohammad Dalour Hossen,Jamari Saidatul Shima Binti
Five different types of acid anhydrides such as succinic anhydride (SA), maleic anhydride (MA), phthalic anhydride (PA), 3,4,5,6-tetrahydrophthalic anhydride (TPA) and cis -1,2-cyclohexanedicarboxylic anhydride (CDA) were used to prepare various polyalkyd resins from palm oil by following alcoholysis and esterification reaction. Palm oil was subjected to dehydration process using concentrated sulphuric acid prior to alcoholysis to improve the unsaturation in the fatty acid chains. Various physicochemical properties of the resins such as acid value, iodine value, yield, density, specific gravity, molecular weight, non-volatile material content, drying time, colour, solubility, etc., were tested by using standard methods. The resins were cured by using methyl ethyl ketone peroxide (MEKP), styrene and cobalt naphthenate at 120 °C. To enhance the thermal, structural and other resinous properties, 0.5 wt% of montmorillonite nanoclays (MNCs) was dispersed in TPA-based resin. The cured films were tested for X-ray diffraction, surface morphology, tensile properties, pencil hardness, gloss, gel content, swelling ratio, adhesion, thermogravimetric analysis, and chemical resistivity. In addition, hydrophobicity of the cured films was observed by contact angle measurement. A comparison was drawn among the resins as well as the films prepared from different acid anhydrides. Analysis revealed that TPA-based resin/film shows improved characteristics among the others due to high degree of crosslinking. On the other hand, incorporation of MNCs into the polyalkyds led to higher thermal properties, acceptable pencil hardness and reduced wettability, which may suit this film to be applied for high-performance surface coating applications.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Shihan Zhang,Mine Du,Peijing Shao,Lidong Wang,Jiexu Ye,Jun Chen,Jianmeng Chen
Carbonic anhydrase (CA) enzyme-based absorption technology for CO2 capture has been intensively investigated. The main issue related to this novel technology is the activity and stability of the CA enzyme under the typical flue gas conditions. To address this issue, CA enzymes were embedded into zeolitic imidazolate framework (ZIF-L) nanoparticles to synthesize a novel CA/ZIF-L-1 composite. The composite exhibited a superior apparent catalytic activity (1.5 times higher) for CO2 absorption compared with their free counterparts, which was due to the synergistic enhancement of CO2 adsorption by support ZIF-L and enzymatic catalysis. The analyses of Fourier transform infrared spectroscopy and circular dichroism revealed that the CA enzyme’s secondary structure was not significantly varied during the CA/ZIF-L-1 preparation, resulting in a high enzyme activity retention. Moreover, the CA/ZIF-L-1 possessed a high thermal stability and reusability due to the structural rigidity and confinement of ZIF-L scaffolds. Compared with the free enzyme, its thermal stability was improved by approximately 100% at 40 °C. After six cycles of reuse, CA/ZIF-L-1 still retained a relative activity of 134%. Therefore, the CA/ZIF-L-1 can be a good candidate to promote the CO2 capture in industrial application.
研究领域:
生物化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Yanfang Hu,Liang He,Jianxun Ding,Diankui Sun,Li Chen,Xuesi Chen
Graphene-based nanocarriers show great potential in photo-chemotherapy, however, to prepare desired reduced graphene oxide (rGO) nanoparticles in a facile way is still a challenge. Herein, a novel strategy has been presented to prepare rGO nanoparticle using dextran (Dex) as a reducing agent. In this strategy, Dex was directly conjugated on rGO by hydrogen bond and then self-assemble to form rGO/Dex nanoparticles. After decorated by dextran, rGO-based nanoparticles not only show excellent biocompatibility but also can load anticancer drug for photo-chemotherapy. The data of fourier transform infrared (FT-IR) analysis, Raman spectrum analysis, thermos-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), the transmission electron microscope (TEM) image and dynamic light scattering (DLS) measurements powerfully proved that the stable rGO-based nanoparticles with desired nanosize have been successfully prepared. To verify the photo-chemotherapy, anticancer drug, doxorubicin (DOX), has been loaded on rGO/Dex nanoparticles (rGO/DOX/Dex). And RGD, a kind of oligopeptide which can improve the intracellular uptake by α v β 3 recognition, also has been introduced (rGO/DOX/RDex). Compared with single chemotherapy, rGO/DOX/Dex and rGO/DOX/RDex combining the local specific chemotherapy and external near-infrared (NIR) photo-thermal therapy show higher therapeutic efficacy, endowing the desired rGO-based nanoparticle with great potential for cancer treatments.
研究领域:
纳米医学
·
肿瘤学
·
生物材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Plasmonics
·
2024
·
IF 3.3
Lv Xianfa,Shi Tongrui,Bai Xia,Guan Zheng,Wang Huanran,Jiang Rujian,Zhou Lu,Chen Hongyu
Creatinine level is a crucial indicator in the clinical assessment and diagnosis of renal diseases, and achieving simple and accurate detection of urinary creatinine levels in resource-limited point-of-care settings is of great significance in the timely prevention and diagnosis of kidney diseases. As a popular zero-dimensional material, gold nanoparticles (AuNPs) exhibit intriguing optical properties and thus have become a promising material for many sensing detection applications. Here, we proposed a simple, efficient, and sensitive quantitative detection of creatinine by studying the relative absorbance (Δ A ) of AuNPs in absence and presence of creatinine. The method relies on the aggregation of AuNPs via ligand-exchanged of citrate ions and creatinine on the surface of AuNPs to achieve colorimetric detection. With this assay, the limit of detection for creatinine was as low as 0.16 mM, and the dynamic detection range was 0.5 to 20 mM under optimized conditions. In our experiments, the specificity of the proposed method was investigated and successfully applied to detect creatinine in urine sample. It reveals that the proposed colorimetric protocol has demonstrated a high sensitivity and selectivity for creatinine, and has a potential practicability in clinical diagnostics.
研究领域:
医学诊断
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纳米材料科学
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临床化学
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2020
·
IF 3.421
Peijing Shao,Han Chen,Qin Ying,Shihan Zhang
In order to fulfill the application of carbonic anhydrase (CA) in the carbon dioxide capture process, immobilization technology will be used to enhance the stability of the enzyme. The structure of the support for the enzyme immobilization is important to determine the enzyme activity and stability. In this work, mesoporous molecular sieves with different dimensions and pore sizes were used as supports for the immobilization of CA. Characterization analysis indicated that the carrier material retained its integrity after enzyme immobilization. The half-life (t1/2) of CA/KIT-6, CA/SBA-15, and CA/MCM-41 increased to 3.0, 2.8, and 2.0 times compared to the free CA enzyme. Additionally, the experimental results showed that when using SBA-15 with a two-dimensional structure and a large pore size as the carrier, the CA enzyme loading was high and retained 78% relative activity and 98% initial activity after 6 days at 40 °C. Comprehensively, CA/SBA-15 was more suitable for capturing CO2 in flue gas than CA/MCM-41 and CA/KIT-6.
研究领域:
生物化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Siying Ye,Yonghui Zhang,Jun Chen,Fuquan Chen,Huifen Weng,Qiong Xiao,Anfeng Xiao
Agar is modified by chemical methods to improve its functional properties and meet the increasing demand of the market. Some of the functional properties of agar are improved after chemical modification, while other properties are reduced, especially gel strength. This study aimed to comprehensively improve the functional properties of agar through acylation and crosslinking by reacting with maleic anhydride. 13 C NMR indicated the maleylation reaction was preferred at the C2 hydroxyl group of D-galactose, and the crosslinking reactions occurred at the C2 and C6 hydroxyl groups of D-galactose in different agar chains. Interestingly, the maleylated agar monoester had higher gel transparency (1.5%, w/v) of up to 76% than the native agar (58%). However, it showed a significant decrease in gel strength from 783 g/cm 2 to 403 g/cm 2 , while crosslinking endowed agar with higher gel strength (845 g/cm 2 ) and gel transparency (78.4%). The high transparency of the modified agar plate made colony observation and colony counting easy. Maleylation of agar further enhanced the freeze–thaw stability of agar gel (24.8%, 7th freeze–thaw cycles). Overall, the maleylated agar possessed superior functional properties, and it could be used as food, bacteriological, and biotechnological agar.
研究领域:
食品科学
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生物技术
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化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 7
·5961-5970
·
IF 3.442
Luo Shuai,Qiao Xuan,Wang Qiu-Yu,Zhang Yun-Fei,Fu Ping,Lin Zhi-Dong,Du Fei-Peng,Cheng Chun
To develop low-cost and high-performance self-healing antifogging coatings, polyvinyl alcohol/hydrolyzed poly(styrene-co-maleic anhydride) (PVA/H-PSMA) coatings were prepared from a mixed solution of polyvinyl alcohol (PVA) and hydrolyzed poly(styrene-co-maleic anhydride) (H-PSMA) via spin coating and annealing. The microstructure, antifogging behavior, and self-healing ability were investigated. High transparency and low surface roughness were observed when the PVA/H-PSMA film was coated on glass slides. The PVA/H-PSMA coatings showed excellent antifogging performance in a warm, humid environment. The coatings also performed well when transferred from a refrigerator to room temperature. The antifogging coatings showed desirable water resistance due to strong chemical bonding between PVA and H-PSMA, as well as excellent self-healing ability due to hydrogen bonding self-assembly in the PVA/H-PSMA structure. The coatings still exhibited excellent antifogging effects after 20 scratching-repairing cycles, illustrating their potential use in practical applications.
研究领域:
材料科学
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Jinghao He,Dejun Dong,Fan Yang,Lihui Sun,Xing Yu,Zhanping Yang,Xuedong Zhu,Yinchun Liang
In the present study, the solid–liquid phase diagrams of four systems acetic acid + acetic anhydride, propionic acid + acetic anhydride, butyric acid + acetic anhydride, and pentanoic acid + acetic anhydride were determined by differential scanning calorimetry at atmospheric pressure. The experimental results illustrated that these systems showed a eutectic behavior. The experimental data were compared with predicted data acquired by solving the phase equilibrium equations using an algorithm. The liquid-phase activity coefficients were calculated by the Wilson and nonrandom two-liquid activity coefficient models. The results show that the approaches used for the calculated system equilibrium was capable to accurately describe the eutectic solid–liquid phase diagrams of the above-mentioned systems.
研究领域:
物理化学
·
热力学
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产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 22
·52234
·
IF 3.057
Changkai Linghu,Lijin Xie,Le Yang,Xiaolong Li,Yao Tao,Yinhan Xu,Zhu Luo
Grafted maleic anhydrides (MAHs) are common compatibilizers, and the Epoxy (EP) group exhibits high activity of epoxy functional groups and strong affinity with both acidic and basic groups. Therefore, high efficiency and broad-spectrum compatibilizers can be obtained by grafting these two monomers onto the polymer molecular chain. In this study, the grafted MAH was used as the graft platform to add the second graft monomer, and the bisphenol A epoxy resin (E51) with two epoxy functional groups or the tri-epoxy functional triglycidyl isocyanurate (TGIC), was added into the polylactic acid molecular chain, in order to prepare the double-monomer grafted PLA compatibilizers. Three kinds of compatibilizers, polylactic acid grafted maleic anhydride (PLA-g-MAH), polylactic acid double grafted maleic anhydride/bisphenol A epoxy resin (PLA-g-MAH-E51), and polylactic acid double grafted maleic anhydride/triglycidyl isocyanurate (PLA-g-MAH-TGIC) were successfully prepared using this single-step method. Finally, FTIR and 1 H-NMR were adopted to measure the grafting degrees and structures of the grafted products. The grafting degree of PLA-g-MAH20% was 5.36%, the MAH and EP grafting degrees of PLA-g-MAH 20%-E51 6% were 2.47% and 1.15%, respectively, and the MAH and EP grafting degrees of PLA-g-MAH 20%-TGIC6% were 2.30% and 0.93%, respectively. A portion of that EP was grafted onto the PLA molecular chain by reacting with grafted anhydride, resulting in a decrease in the number of grafted anhydride groups.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Haoyu Li,Pengfei Wu,Xianquan Li,Jifeng Pang,Shangru Zhai,Tao Zhang,Mingyuan Zheng
High-performance MFI zeolite supported nickel catalysts were prepared by the ammonia evaporation method for maleic anhydride (MA) conversion to γ-butyrolactone (GBL). According to comprehensive characterizations, the Ni catalysts possessed petal-like morphology and hierarchical structures with meso and micro pores. Nickel species were highly dispersed on the silica support and generated abundant Lewis acid sites (LAS), which effectively activated carbonyl groups in the reactant and accounted for the high activity in MA hydrogenation. Zr species hydrothermally introduced into the catalyst increased the number of LAS and decreased the apparent activation energy for the reaction. The highest GBL yield reached 95.6% over 40Ni-2Zr-MFI with the assistance of 3A zeolite to in-situ remove water byproduct. The catalyst showed reasonably good stability in five-cycle operation thanks to the strong interaction between Ni and support. The reaction route for MA hydrogenation was investigated, in which succinic anhydride (SA-A) served as the major reaction intermediate for GBL formation.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2023
·
IF 6
Jie Li,Shufeng Liu,Ge Zhu,Chunshan Lu,Yuxia Ba,Guofei Chen,Xingzhong Fang
Two isomeric dianhydride monomers, 1,4-bis(3,4-dicarboxyphenoxy)-2- tert -butylbenzene dianhydride (4,4′-TBHQDA) and 1,4-bis(2,3-dicarboxyphenoxy)-2- tert -butylbenzene dianhydride (3,3′-TBHQDA), were successfully synthesized from tert -butylhydroquinone and nitrophthalonitrile. Two series of polyetherimides (PEIs) were synthesized by chemical imidization using the above dianhydrides with four common commercially available diamines. The effects of dianhydrides with isomerization and tert -butyl group on the thermal properties, optical properties, melt processability, solubility, and mechanical properties of PEIs were systematically studied. Among them, PEI-2(a-d) derived from 3,3′-TBHQDA displayed better comprehensive performance than other PEIs, which showed well T g s at 234–261 ℃, good optical properties of 82–86 % at 450 nm, extremely low melt viscosities of 30–59 Pa·s at 400 ℃, excellent solubility and good mechanical properties (tensile modulus of 2.7–3.5 GPa, tensile strengths of 90–97 MPa and elongations at break of 3.4–4.8 %).
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）